1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/acpi.h> 3 4 #include <xen/hvc-console.h> 5 6 #include <asm/bootparam.h> 7 #include <asm/io_apic.h> 8 #include <asm/hypervisor.h> 9 #include <asm/e820/api.h> 10 #include <asm/x86_init.h> 11 12 #include <asm/xen/interface.h> 13 14 #include <xen/xen.h> 15 #include <xen/interface/hvm/start_info.h> 16 17 /* 18 * PVH variables. 19 * 20 * pvh_bootparams and pvh_start_info need to live in a data segment since 21 * they are used after startup_{32|64}, which clear .bss, are invoked. 22 */ 23 struct boot_params __initdata pvh_bootparams; 24 struct hvm_start_info __initdata pvh_start_info; 25 26 const unsigned int __initconst pvh_start_info_sz = sizeof(pvh_start_info); 27 28 /* 29 * Xen guests are able to obtain the memory map from the hypervisor via the 30 * HYPERVISOR_memory_op hypercall. 31 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 32 * will have been configured to provide an override for this routine to do 33 * just that. 34 */ mem_map_via_hcall(struct boot_params * ptr __maybe_unused)35void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused) 36 { 37 xen_raw_printk("Error: Could not find memory map\n"); 38 BUG(); 39 } 40 init_pvh_bootparams(bool xen_guest)41static void __init init_pvh_bootparams(bool xen_guest) 42 { 43 if ((pvh_start_info.version > 0) && (pvh_start_info.memmap_entries)) { 44 struct hvm_memmap_table_entry *ep; 45 int i; 46 47 ep = __va(pvh_start_info.memmap_paddr); 48 pvh_bootparams.e820_entries = pvh_start_info.memmap_entries; 49 50 for (i = 0; i < pvh_bootparams.e820_entries ; i++, ep++) { 51 pvh_bootparams.e820_table[i].addr = ep->addr; 52 pvh_bootparams.e820_table[i].size = ep->size; 53 pvh_bootparams.e820_table[i].type = ep->type; 54 } 55 } else if (xen_guest) { 56 mem_map_via_hcall(&pvh_bootparams); 57 } else { 58 /* Non-xen guests are not supported by version 0 */ 59 BUG(); 60 } 61 62 if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) { 63 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr = 64 ISA_START_ADDRESS; 65 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size = 66 ISA_END_ADDRESS - ISA_START_ADDRESS; 67 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type = 68 E820_TYPE_RESERVED; 69 pvh_bootparams.e820_entries++; 70 } else 71 xen_raw_printk("Warning: Can fit ISA range into e820\n"); 72 73 pvh_bootparams.hdr.cmd_line_ptr = 74 pvh_start_info.cmdline_paddr; 75 76 /* The first module is always ramdisk. */ 77 if (pvh_start_info.nr_modules) { 78 struct hvm_modlist_entry *modaddr = 79 __va(pvh_start_info.modlist_paddr); 80 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr; 81 pvh_bootparams.hdr.ramdisk_size = modaddr->size; 82 } 83 84 /* 85 * See Documentation/arch/x86/boot.rst. 86 * 87 * Version 2.12 supports Xen entry point but we will use default x86/PC 88 * environment (i.e. hardware_subarch 0). 89 */ 90 pvh_bootparams.hdr.version = (2 << 8) | 12; 91 pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0; 92 93 pvh_bootparams.acpi_rsdp_addr = pvh_start_info.rsdp_paddr; 94 } 95 96 /* 97 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 98 * will have been configured to provide the required override for this routine. 99 */ xen_pvh_init(struct boot_params * boot_params)100void __init __weak xen_pvh_init(struct boot_params *boot_params) 101 { 102 xen_raw_printk("Error: Missing xen PVH initialization\n"); 103 BUG(); 104 } 105 hypervisor_specific_init(bool xen_guest)106static void __init hypervisor_specific_init(bool xen_guest) 107 { 108 if (xen_guest) 109 xen_pvh_init(&pvh_bootparams); 110 } 111 112 /* 113 * This routine (and those that it might call) should not use 114 * anything that lives in .bss since that segment will be cleared later. 115 */ xen_prepare_pvh(void)116void __init xen_prepare_pvh(void) 117 { 118 119 u32 msr = xen_cpuid_base(); 120 bool xen_guest = !!msr; 121 122 if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) { 123 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n", 124 pvh_start_info.magic); 125 BUG(); 126 } 127 128 /* 129 * This must not compile to "call memset" because memset() may be 130 * instrumented. 131 */ 132 __builtin_memset(&pvh_bootparams, 0, sizeof(pvh_bootparams)); 133 134 hypervisor_specific_init(xen_guest); 135 136 init_pvh_bootparams(xen_guest); 137 } 138